Landmark

ABSTRACT

A body is formed of rigid synthetic material and the lower end portion of the body has an integral screw thread formed thereon. A metallic helix of cork screw shape has the upper end thereof embedded in the lower part of the body and the helix extended downwardly from the lower end of the body. A central stepped bore extends longitudinally through the body and is adapted to receive a tool extending downwardly through the bore. Longitudinally extending ribs are provided within the bore for engaging a tool to enable rotation of the body by the tool. Suitable landmark means such as a cap, a flat plate or a geodesic beacon is adapted to be supported at the upper end of the body. A closure means is provided for closing off the upper end of the bore formed through the body or through a landmark means such as a cap.

[451 Sept. 5, 1972 United States Patent Wolicarius [54] LANDMARK FOREIGN PATENTS OR APPLICATIONS 577 5055 1711 2222 555 v n n n mBBB mama emmm GGGG 0 58 1M6.) 9999 1111 4026 l 5 58 iwsz 2&400 2 009 2597 e d m l m 8 m1 1 1 mm 7 Km U o WM 3 em h mom "an O m a w i h F 2 2 U U 21 Appl. No.: 129,887

Primary Examiner-Henry C. Sutherland Related US. Application Data Att0mey Fred C Philpitt [63] Continuation-impart of Ser. No. 792,028, Jan.

[57] ABSTRACT A body is formed of rigid synthetic material and the 17, 1969, abandoned.

[52] US. Cl. .........................52/103, 52/127, lower end portion of the body P integral Screw 6 127 thread formed thereon. A metallic helix of cork screw shape has the upper end thereof embedded in the lower part of the body and the helix extended [58] Field of 52/155, 157, 705

downwardly from the lower end of the body. A central [56] References Cited UNITED STATES PATENTS stepped bore extends longitudinally through the body and is adapted to receive a tool extending downwardly through the bore. Longitudinally extending ribs are provided within the bore for engaging a tool to enable rotation of the body by the tool. Suitable landmark means such as a cap, a flat plate or a geodesic beacon is adapted to be supported at the upper end of the body. A closure means is provided for closing off the upper end of the bore formed through the body or through a landmark means such as a cap.

9 Claims, 10 Drawing Figures LANDMARK The present application is a continuation-in-part of my co-pending U.S. Pat. application, Ser. No. 792,028, filed Jan. 17, 1969 and now abandoned.

BACKGROUND OF THE INVENTION The present invention relates to a landmark which is adapted to be driven into the ground and utilized in operations such as surveying, topography, geodesy, public works, etc.

In the past, some landmarks which have been adapted to be driven into the ground have been made of metal covered with synthetic material which is provided near its base with one or two helical turns or screw threads to facilitate introduction of the landmark into the ground. This type of landmark does not possess sufficient stability, and furthermore, if the plastic coating is accidentally removed, the underlying metal is oxidized and the landmark soon deteriorates.

Conventional landmarks are difficult to properly center and to drive into the ground in proper vertical alignment. Additionally, known types of landmarks are rather difficult to remove.

SUMMARY OF THE PRESENT INVENTION The present invention comprises a body made of rigid synthetic material, the lower end of which defines on the outer surface thereof an integral screw thread. A metallic helix of corkscrew shape has the upper end thereof threaded in the lower part of the body and the lower end of the helix extends downwardly from the lower end of the body and defines a continuation of the screw threads on the body. A central bore extends longitudinally through the body and is stepped to provide an intermediate shoulder thereon which receives a tool. In addition, a plurality of longitudinally extending ribs project radially into the bore for engagement with the tool. In addition, a plurality of longitudinally extending ribs project radially into the bore for engagement with the tool. With this construction, the tool is adapted to exert downward force on the body and additionally can rotate the body so as to effectively drive the body downwardly into the ground.

The upper portion of the metallic helix extends within the threaded portion of the body and serves to reinforce the integral screw threaded portion of the body.

Closure means is provided for closing off the upper end of the bore formed through the body. Slot means are formed in the upper end of the bore of the body and cooperate with the lugs on the closure means to hold the closure means in position.

A cap may be supported at the upper end of the body means and has a bore formed therethrough which is also adapted to be closed off by the closure means when the cap is in use. Slot means is formed in the cap for holding the closure means in position.

A plate may also be supported at the upper end of the body, the plate having a central hole formed therethrough which receives a lip formed on the body. This plate is held in operative position by the closure means.

In addition to the aforementioned arrangements, a geodesic beacon may also be supported at the upper end of the body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top perspective of a landmark according to the present invention;

FIG. 2 is a longitudinal section taken substantially along line 2-2 of FIG. 1 looking in the direction of the arrow;

FIG. 3 is a sectional view taken substantially along line 33 of FIG. 2 looking in the direction of the arrows;

FIG. 4 is a sectional view taken substantially along line 4-4 of FIG. 2 looking in the direction of the arrows:

FIG. 5 is a sectional view taken substantially along line 5-5 of FIG. 2 looking in the direction of the arrow;

FIG. 6 is a top perspective view illustrating a modified form of the invention;

FIG. 7 is a top view on an enlarged scale of a portion of the structure shown in FIG. 6;

FIG. 8 is a sectional view taken substantially along line 8-8 of FIG. 7 looking along the direction of the arrows;

FIG. 9 is a top perspective view of a tool utilized for driving the landmark into the ground; and

FIG. 10 is an elevation of still another modified form of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings wherein like reference characters designate corresponding parts throughout the several views, a first form of the invention is illustrated in FIGS. 1-5 inclusive. As seen in these figures, the landmark includes a body 20 formed of a suitable rigid synthetic material such as plastic, the lower end portion of the body having an integral screw thread 22 formed on the outer surface thereof. A metallic helix 24 formed of stainless steel or the like has the upper end thereof embedded in the lower part of the body whereby the upper end of the helix serves to reinforce the screw thread formed on the body. The upper end of the helix is substantially coextensive with the upper end of the screw thread formed on the body. The lower end of the helix extends downwardly from the lower end of the body and forms a continuation of the screw thread on the body, the helix terminating in a pointed end 26.

A central bore extends longitudinally through the body and includes a first bore portion 30 and a second bore portion 32 of less dimension whereby an angular shoulder 34 is provided intermediate to two bore portions.

A plurality of longitudinally extending ribs 38 are formed integral with the body and projects radially inwardly into the bore portion 30.

Referring now to FIG. 9, a tool is illustrated suitable for driving the landmark into the ground. The tool includes an upper horizontal handle portion 40 rigidly connected with a portion 42 of generally rectangular cross-sectional configuration. A further integral portion 44 extends downwardly from portion 42 and terminates in a sharpened pointed lower end 46. The tool is illustrated in phantom lines in FIG. 2 in its operative position for driving the landmark into the ground. The tool extends downwardly through the bore formed in the body and the lower end of portion 42 is adapted to rest on shoulder 34 formed within the body so that a downward force may be exerted on the body of the landmark. It will additionally be noted that the lower pointed end 46 of the tool extends downwardly below the lower end of the helix by an amount of approximately an inch so as to assure accurate centering of the landmark.

When it is desired to drive the landmark into the ground, the tool is inserted in a position shown in FIG. 2 and downward force applied thereto. The tool should be sufficiently strong so as to be able to withstand hammer blows which may be necessary to facilitate introduction of the landmark into the ground. As seen in FIGS. 3 and 4, the portion 42 of the tool is adapted to cooperate with the ribs 38 formed within the body whereby rotation of the tool is translated to body causing the body to be rotated along with the tool.

As seen most clearly in FIGS. 2 and 5, a flange 50 of generally square plan configuration is formed integral with the upper end of the body. A pair of substantially diametrically opposed bayonet slots 52 are formed in the material of the body at opposite sides of the bore, and a pair of through holes 54 are formed through the wall of the body and intersect the horizontal portions of the bayonet slots.

A cap indicated generally by reference character 70 is supported at the upper end of the body and is of generally square cross-section configuration. The cap includes an upper wall 64 from which depends outer side walls 66, intermediate side walls 68 and a central tubular wall 70 of general cylindrical cross-section. Bayonet slots 72 are formed in inner wall 70 at substantially diametrically opposite portions of a central bore 74 formed through the cap, this central bore being adapted to being coaxially aligned with the bore portion 30 of the body means as seen in the drawings. Retaining portions 76 are provided at the four corners of the intermediate walls 68, these retaining portions being adapted to be snapped over the corners of flange 50 formed at the upper end of the body for holding the cap in the operative position illustrated. Cap 60 may be formed of the same material as the body which in a typical example may comprise polyethylene. The lip 78 of tapered cross-sectional configuration is formed integral with top wall 64 of the cap and is disposed in surrounding relation to the upper end of the bore 74 formed through the cap. A similar tapered lip 80 is formed integral with the flange 50 at the upper end of the body and is disposed in surrounding relationship to the upper end of bore portion 30 formed through the body.

As seen most clearly in FIG. 2, closure means is indicated generally by reference character 90 and includes a cylindrical body portion 92 adapted to fit snugly within either the bore portion 30 of the body or the bore portion 74 of the cap. A laterally extending angular flange 94 is formed at the upper end of the closure means and includes a flat under surface adapted to rest upon the upper-edge of lip 78 or lip 80. The closure means is provided with a recess 96 of hexagonal configuration as seen from above for receiving a suitable wrench adapted to move the closure means into and out of operative position.

A pair of diametrically opposite laterally extending lugs 98 are formed on the outer surface of the lower end of the closure means and are adapted to cooperate with the bayonet slots formed either in the cap or in the body. As illustrated in FIG. 2, the closure means is employed for closing off the upper end of the bore formed through the cap.

Referring now to FIGS. 6-8 inclusive, a modified form of the invention is illustrated wherein a flat plate 100 is supported at the upper end of the body. This form of the invention is particularly suitable for use in fields where tractors or the like may ride over the plate without displacing the landmark and without interfering with the movement of the tractor. As seen in FIG. 8, plate 100 is provided with a central hole 102 which is adapted to receive lip formed at the upper end of the body. Closure means is held in the operative position shown by intercooperation of the lugs formed on the closure means and the bayonet slots provided within the body. It is apparent that flange 94 of the closure means serves to hold the plate in position.

Referring now to FIG. 10 of the drawings, a geodesic beacon is illustrated including a beacon portion supported at the upper end of the tubular part 1 12. Part 112 is in turn connected with a downwardly extending portion 114 formed integral with a supporting base 116. The base 116 can in turn be supported by flange 50 of the body in a manner similar to the manner in which plate 100 is supported in operative position.

In conclusion, while there has been illustrated and described a preferred embodiment of my invention, it is to be understood that since the various details of construction may obviously be varied considerably without really departing from the basic principles and teachings of this invention, l do not limit myself to the precise constructions herein disclosed and the right is specifically reserved to encompass all changes and modifications coming within the scope of the invention as defined in the appended claims.

What is claimed is:

l. A landmark comprising a body made of rigid synthetic material, the lower end portion of said body defining on the outer surface thereof an integral screw thread, a metallic helix of corkscrew shape having the upper end thereof embedded in the'lower part of said body with the lower end of said helix extending downwardly from the lower end of said body and defining a continuation of the screw thread on said body, a central bore extending longitudinally through said body and being aligned with an open space within said helix for receiving a tool extending downwardly through said bore and being adapted to drive the landmark into the ground, means formed on said body in the upper portion of said bore and projecting into the bore for engaging said tool for imparting rotation to said body to drive same into the ground.

2. A landmark as defined in claim 1 wherein said bore through said body is stepped to form a bore portion of greater dimension in the upper part of said body and a bore portion of less dimension in the lower part of said body so as to form an intermediate shoulder adapted to engage a tool.

3. A landmark as defined in claim 1 wherein said means formed on said body comprises a plurality of longitudinally extending rib means which are angularly spaced from one another and which project radially into said bore.

4. A landmark as defined in claim 1 wherein the upper end of said metallic helix extends within the screw threads formed on said body and serves to reinforce said screw thread.

5. A landmark as defined in claim 1 including closure means, said closure means and said body including cooperating means for holding said closure means in place within the upper end of said bore to close off the upper end of said bore.

6. A landmark as defined in claim 6 wherein said cooperating means comprises slot means formed in said body means and lug means on said closure means.

7. A landmark as defined in claim 1 including a cap supported at the upper end of said body, said cap having a bore formed therethrough adapted to be aligned with said bore formed in the body, and slot means formed in said cap for holding a cooperating closure means in place to close ofi the upper end of the bore formed through said cap.

8. A landmark as defined in claim 1 including a plate supported at the upper end of said body, said plate having a hole formed therethrough, a lip formed on said body means and received within said hole, and a closure means extending through said hole and being disposed within the upper end of said bore, said closure means serving to hold said plate in place and to close off the upper end of said bore.

9. A landmark as defined in claim 1 including a 

1. A landmark comprising a body made of rigid synthetic material, the lower end portion of said body defining on the outer surface thereof an integral screw thread, a metallic helix of corkscrew shape having the upper end thereof embedded in the lower part of said body with the lower end of said helix extending downwardly from the lower end of said body and defining a continuation of the screw thread on said body, a central bore extending longitudinally through said body and being aligned with an open space within said helix for receiving a tool extending downwardly through said bore and being adapted to drive the landmark into the ground, means formed on said body in the upper portion of said bore and projecting into the bore for engaging said tool for imparting rotation to said body to drive same into the ground.
 2. A landmark as defined in claim 1 wherein said bore through said body is stepped to form a bore portion of greater dimension in the upper part of said body and a bore portion of less dimension in the lower part of said body so as to form an intermediate shoulder adapted to engage a tool.
 3. A landmark as defined in claim 1 wherein said means formed on said body comprises a plurality of longitudinally extending rib means which are angularly spaced from one another and which project radially into said bore.
 4. A landmark as defined in claim 1 wherein the upper end of said metallic helix extends within the screw threads formed on said body and serves to reinforce said screw thread.
 5. A landmark as defined in claim 1 including closure means, said closure means and said body including cooperating means for holding said closure means in place within the upper end of said bore to close off the upper end of said bore.
 6. A landmark as defined in claim 6 wherein said cooperating means comprises slot means formed in said body means and lug means on said closure means.
 7. A landmark as defined in claim 1 including a cap supported at the upper end of said body, said cap having a bore formed therethrough adapted to be aligned with said bore formed in the body, and slot means formed in said cap for holding a cooperating closure means in place to close off the upper end of the bore formed through said cap.
 8. A landmark as defined in claim 1 including a plate supported at the upper end of said body, said plate having a hole formed therethrough, a lip formed on said body means and received within said hole, and a closure means extending through said hole and being disposed within the upper end of said bore, said closure means serving to hold said plate in place and to close off the upper end of said bore.
 9. A landmark as defined in claim 1 including a geodesic beacon suPported at the upper end of said landmark. 